The Logitech MX518 is a computer and gaming mouse. I purchased the Logitech MX518 online from newegg.com for $24.99 (originally $39.99, with a coupon code and mail-in rebate) in late November 2008. I upgraded from a Logitech MX310, another laser mouse, to the Logitech MX518. Movement of the mouse was smoother. Like its predecessor, the additional buttons on the mouse, other than the standard right and left buttons, made navigating easier. I was able to conveniently click one of the side buttons to go back to a previous page on a website or file folder without having to move my mouse, although I don't use the extra buttons as often now. The warranty of the product is 3 years, which is quite advantageous for a simple computer mouse.
I found that the MX518 is indeed more suitable for gaming purposes than the MX310. More specifically, the MX518 has an uneven shape that takes into account the natural resting of the hand. If you look at the mouse from eye level, you can see a slant downward to the right button side; the MX310 does not have this. I suppose the term is that the MX518 is more "ergonomic" than the MX310.
The mouse wheel, though seemingly an inconsequential feature, is worth mentioning. When the mouse wheel of the MX518 is rotated, one can feel a distinct locked position of each turn. In an online FPS shooter like CounterStrike Source (2004), the wheel is generally used for switching weapons. When I used the Logitech MX310 for games, the mouse wheel would be unreliable. Sometimes I would attempt to switch to a weapon with the wheel, only to switch to a different one or one that I did not intend to; this occurred because the wheel did not lock into position and was prone to being accidentally nudged. In everyday computer usage, such as scrolling a page on a website, it can also be important to have a mouse wheel that is constructed well.
There are several drawbacks to the MX518. The included CD has a lot of unnecessary software. The only reason to install said software is for the ability to assign specific tasks to the extra buttons, but I did not feel the need to do so. In my previous experience with the Logitech MX310, a message would periodically pop up on my screen that would ask me to register my product on the Logitech website, which was annoying. The software can be uninstalled easily enough though and may not be needed for you to install in the first place.
In addition, I have noticed that the mouse pointer on my screen will inexplicably jump to another part of the screen that I did not intend it to from time to time. It does not happen enough to warrant a return, but it can be a temporary inconvenience. This experience may vary among different people since the use of mice and their initial quality differ.
In conclusion, the Logitech MX518 can be used for both basic computing and gaming purposes. I would advise purchasing it at a low price (preferably below $30.00); I actually saw it retail for $8.00 at the now-bankrupt Circuit City a few months ago. There are more expensive alternatives, such as the Logitech G5 or G9, but I find that the MX518 suits my needs adequately.